Fluid level controller

ABSTRACT

A controller and method of using same are disclosed. Preferably, the controller includes a pilot cartridge housing supporting an invertible pilot cartridge assembly (“cartridge”). The cartridge preferably includes a cartridge body supporting a number of pneumatic seals adjacent the housing, wherein at least two of the seals are diaphragms. The cartridge preferably provides a first pilot activation feature and an opposing second pilot activation feature. The operating mode of the cartridge is determined by a selected orientation of the first pilot activation feature relative to the housing; and preferably the method of operating the controller includes the steps of: selecting an orientation of the first pilot activation feature relative to the housing; setting a span control mechanism to a neutral position relative to the housing; adjusting a float communicating with the cartridge to a neutral position; and adjusting said span control mechanism to determine a response type of said cartridge.

FIELD OF THE INVENTION

This invention relates to new and useful improvements in fluid levelcontrollers that incorporate pilot pressure control devices.

BACKGROUND

Controllers are known to utilize pressurized fluid to actuate a unit,such as a motor valve, to control a primary variable condition, such asa fluid level confined within a storage vessel, by maintaining the fluidlevel within the storage vessel within predetermined limits. Changes inthe fluid level within the storage vessel are used by the controller toselectively apply the pressurized fluid to the unit, such as a motorvalve controlling the flow of fluid through an inlet line attached tothe storage vessel. Other applications and uses for pressurized fluidcontrollers are well known in the art.

One type of pressurized fluid control device is epitomized by thepressure control device disclosed within U.S. Pat. No. 3,102,241 issuedto Asbury S. Parks on Feb. 4, 1964 (Parks '241). Although Parks '241discloses a functional controller, controllers utilizing the technologydisclosed by Parks '241 inherently present a number of drawbacksincluding: the encountering of significant downtime when defectivediaphragms need replacement; and the need to reconfigure the pilotpressure control device, which interacts with the fluid level detectionmechanism to control the fluid level within the vessel, and to change tooperating mode of the controller from a direct mode to an indirect mode.

Accordingly, as market pressures continue to demand liquid levelcontrollers that provide lower cost, greater reliability, and improvedease of use, challenges remain and a need persists for improvements inmethods and apparatuses for use in fluid level monitoring and controldevices.

SUMMARY OF THE INVENTION

In accordance with preferred embodiments, a controller includes at leasta pilot cartridge housing (“cartridge housing”) and an invertible pilotcartridge assembly (“cartridge”) supported by the cartridge housing, inwhich the cartridge preferably includes a cartridge body supporting aplurality of seals, wherein the seals communicate with the cartridgehousing to pneumatically isolate the cartridge form the cartridgehousing, and at least two of the seals are diaphragms. The preferredembodiment further includes a base plate supporting the cartridgehousing, a linkage shaft communicating with the base plate, and a leveladjustment bar secured to the linkage shaft and configured with atransfer linkage configured for selective communication with either afirst pilot activation feature provided on a proximal end of thecartridge, or a second pilot activation feature provided on a distal endof the cartridge. The operating mode of the cartridge is determined byan orientation of the first pilot activation feature relative to thehousing, and preferably the cartridge responds to an activation of thelevel adjustment bar by generating a control signal.

In an alternate preferred embodiment, a method of operating thecontroller in a direct operating mode preferably includes the steps of:setting a span control mechanism provided by a first pilot activationfeature of the cartridge to a neutral position relative to the cartridgehousing supporting the cartridge; adjusting a float communicating withthe cartridge to a neutral position relative to the cartridge housing;adjusting the span control mechanism to determine a signal response typeof the cartridge; orienting the first pilot activation feature adjacenta detachable cover supported by the cartridge housing to determine adirect operating mode of the cartridge; and securing the detachablecover to the cartridge housing in preparation for operating thecontroller in the direct operating mode.

In an alternative preferred embodiment, a method of operating thecontroller in an indirect operating mode preferably includes the stepsof: setting a span control mechanism provided by a first pilotactivation feature of the cartridge to a neutral position relative to acartridge housing supporting the cartridge; adjusting a floatcommunicating with the cartridge to a neutral position relative to thecartridge housing; adjusting the span control mechanism to determine asignal response type of the cartridge; orienting a second pilotactivation feature adjacent a detachable cover supported by thecartridge housing to determine an indirect operating mode of thecartridge; and securing the detachable cover to the cartridge housing inpreparation for operating the controller in the indirect operating mode.

These and various other features and advantages that characterize theclaimed invention will be apparent upon reading the following detaileddescription and upon review of the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front elevational view of an embodiment of an inventivefluid level controller.

FIG. 2 shows a front elevational view of the controller of FIG. 1 withthe cover removed.

FIG. 3 shows a right side elevational view of the controller of FIG. 1with the cover partially cutaway.

FIG. 4 shows a front elevational, cross-sectional view of an invertiblepilot cartridge of the inventive liquid level controller of FIG. 2.

FIG. 5 shows a front elevational, cross-sectional view of a pilotcartridge housing assembly of the inventive liquid level controller ofFIG. 2.

FIG. 6 illustrates a front elevational, cross-sectional view of theinvertible pilot cartridge of the inventive liquid level controller ofFIG. 2, configured in a direct operation mode.

FIG. 7 illustrates a right side elevational, cross-sectional view of theinvertible pilot cartridge of the inventive liquid level controller ofFIG. 2, configured in a direct operation mode.

FIG. 8 illustrates a front elevational, cross-sectional view of theinvertible pilot cartridge of the inventive liquid level controller ofFIG. 2, configured in an indirect operation mode.

FIG. 9 illustrates a right side elevational, cross-sectional view of theinvertible pilot cartridge of the inventive liquid level controller ofFIG. 2, configured in an indirect operation mode.

FIG. 10 reveals a partial cutaway, bottom plan view of the inventiveliquid level controller of FIG. 3.

FIG. 11 reveals a partial cutaway, top plan view of the inventive liquidlevel controller of FIG. 1.

FIG. 12 shows a method of using the inventive liquid level controller ofFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to one or more examples of theinvention depicted in the figures. Each example is provided by way ofexplanation of the invention, and not meant as a limitation of theinvention. For example, features illustrated or described as part of oneembodiment may be used with another embodiment to yield still adifferent embodiment. Other modifications and variations to thedescribed embodiments are also contemplated within the scope and spiritof the invention.

Referring to the drawings, FIG. 1 shows an inventive fluid levelcontroller 100 (also referred to herein as controller 100) that includesa product cover 102 providing viewing apertures for visual access toboth a fluid supply pressure gauge 104, and a fluid signal pressuregauge 106. The pressure gauges 104 and 106 provide operators of thecontroller 100 with the current status of the fluid associated with thecontroller 100.

FIG. 2 shows the controller 100 further includes a base plate 108, whichsupports a pilot cartridge housing assembly 110 (also referred to hereinas cartridge housing 110) and a displacer housing 112. The cartridgehousing 110 includes a main support structure 114, which provides accessapertures for both the pressure gauges 104 and 106, and a mountingsurface for a detachable cover 116. In a preferred embodiment thedetachable cover 116 is secured to the main support structure 114 by atleast one fastener 118.

The displacer housing 112 preferably supports at least one bearing block120, which in turn preferably supports a linkage shaft 122. The linkageshaft 122 provides a mounting portion 124 for use in mounting a leveladjustment bar 126, which communicates with a transfer linkage 128.During the discussion of FIG. 3, a response of the level adjustment bar126 and transfer linkage 128 to a primary control input, such as thelevel of a fluid within a vessel, will be disclosed in greater detail.

FIG. 2 further shows the cartridge housing 110 confines an invertiblepilot cartridge 130 (also referred to herein as cartridge 130). Thecartridge 130 provides a first thrust pin 132, which includes with afirst pilot activation feature 134; and a second thrust pin 136 (seeFIG. 4), which includes a second pilot activation feature 138 (see FIG.4). The structure of the first thrust pin 132 differs from the secondthrust pin 136 in that the first thrust pin 132 preferably provides athreaded aperture provided for interaction with a span controladjustment mechanism 140. An important feature in a preferred embodimentof the span control adjustment mechanism 140 is an inclusion of anexhaust port 142.

The controller 100 illustrated in FIG. 2 shows the first thrust pin 132is adjacent the detachable cover 116, and the transfer linkage 128communicating with the second thrust pin 136. In this configuration, thecartridge 130 operates in a direct operating mode. As will be disclosedin greater detail during the discussion of FIGS. 4-9, the cartridge isdesigned to be symmetric about a fluid inlet access aperture 186 (seeFIG. 5) of the cartridge housing 110. This symmetry of designfacilitates mounting the second thrust pin of the cartridge 130 adjacentthe detachable cover 116, and attaching the transfer linkage 128 to thefirst thrust pin 132 to operate the cartridge 130 in an indirectoperating mode.

FIG. 3 shows the base plate 108 provides a mounting block 144 forattachment of the cartridge housing 110 to the base plate 108, thedisplacer housing 112 extends through the back of the base plate 108,and is secured to the base plate 108 by an attachment flange 146provided by the base plate 108.

The displacer housing 112 provides access to the linkage shaft 122 for adisplacer arm 148. The level adjustment bar 126 is secured to thelinkage shaft 122 by fasteners 150. A distal end of the displacer arm148 is attached to the linkage shaft 122 (not separately shown), and aproximal end 152 of the displacer arm 148 is secured to a swivelmechanism 154 that further connects with a displacer 156. In response toan interaction of the displacer 156 (also referred to herein as float156) with a rising fluid level the float 156 rises, which causes thedisplacer arm 148 to rise thereby imparting counter clockwise rotationon the linkage shaft 122.

In response to be counter clockwise rotation of the linkage shaft 122,the level adjustment bar 126 rotates in a counter clockwise directioncausing the transfer linkage 128 to impart a downward force on thesecond thrust pin 136. The downward force imparted on the second thrustpin 136 causes a generation of a control signal by the cartridge 130. Asillustrated, the controller 100 is configured with the cartridge 130positioned for operation in the direct acting mode. However, whenconfigured for operation in the indirect operating mode, the cartridge130 generates a control signal in response to a lowering of the float156, typically caused by a lowering of a fluid interacting with thefloat 156.

FIG. 3 further shows the base plate 108 provides support for a threadedshaft 158, which accommodates the level adjustment bar 126, acounterbalance compression spring 160, and a counterbalance adjustmentknob 162. The counterbalance adjustment knob 162 is preferably providedwith a threaded aperture 164 (see FIG. 2), for interaction with thethreaded shaft 158. A clockwise rotation of the counterbalanceadjustment knob 162 causes a counter clockwise rotation of the linkageshaft 122, thereby raising the displacer 156. A counter clockwiserotation of the counterbalance adjustment knob 162 causes a clockwiserotation of the linkage shaft 122, thereby lowering the displacer 156.Having an advantage of being able to adjust the vertical position of thedisplacer 156 relative to the displacer housing 112, will become moreclear during a disclosure of preferred embodiments of methods used forsetting up the controller 100.

In a preferred embodiment shown by FIG. 4, the invertible pilotcartridge 130 includes main cartridge body 165, which support aplurality of seals that include o-rings 166 and a pair of diaphragms168. Preferably, a first of the pair of diaphragms 168 supports thefirst thrust pin 132, and the second of the pair of thrust pins 136. Thefirst and second thrust pins 132, 136 are connected by spacers 170,which serve to transfer fluid between upper and lower portions of asignal chamber 200 (see FIG. 6). Preferably, a retention disc 172 isinterposed between each of the pair of diaphragms 168 and each spacer170. In a preferred operating mode, the thrust pins 132, 136 move inunison causing a change in position of the span control adjustmentmechanism 140 relative to the main cartridge body 165, which controlsthe operation of a valve member 174 (also referred to herein as a peanutvalve 174).

The main cartridge body 165 further provides a pilot spring retentionmember 176, which in a preferred embodiment is a set screw. The pilotspring retention member 176 provides support to and confinement of apilot spring 178 that urges a bottom valve face of the peanut valve 174against a first valve seat 180, provided by the main cartridge body 165.A top valve face of the peanut valve 174 communicates with a secondvalve seat 182, provided by the span control adjustment mechanism 140,to regulate passage of pressurized fluid through the exhaust port 142.Preferably, the pilot spring 178 is contained within a fluid inputchamber 184 provided by the main cartridge body 165.

FIG. 5 shows the main support structure 114 of the cartridge housing 110provides the fluid inlet access aperture 186, an output signal aperture188, a fluid supply pressure gauge aperture 190, a fluid signal pressuregauge aperture 192, a first thrust pin access aperture 194, and aplurality of cover mounting apertures 196. The detachable cover 116provides a second thrust pin access aperture 198.

When the controller 100 (of FIG. 3) is configured for operation in anindirect operating mode, the cartridge 130 (of FIG. 4) is mounted withinthe main support structure 114 of the cartridge housing 110 such thatthe first thrust pin 132 (of FIG. 4) protrudes through the first thrustpin access aperture 194. When the controller 100 is configured foroperation in a direct operating mode, the cartridge 130 is mountedwithin the main support structure 114 of the cartridge housing 110 suchthat the second thrust pin 136 protrudes through the first thrust pinaccess aperture 194.

It will be noted that regardless of whether the controller 100 isconfigured for use in a direct operating mode or an indirect operatingmode, the fluid input chamber 184 (of FIG. 4) (do to its central locatedwithin the main cartridge body 165 (of FIG. 4)) is consistently capableof being aligned for direct interaction and communication with the fluidinlet access aperture 186.

For an enhance understanding of the present invention, FIGS. 6, 7, 8,and 9 should be viewed in concert. In a preferred embodiment, thepresent invention is a liquid level controller, such as controller 100,which utilizes pressurized fluid, such as pressurized air, to operate avalve of a fluid storage vessel. When configured for operation in adirect operating mode, such as that shown by FIGS. 6 and 7, thecontroller is responsive to fluid within the fluid storage vesselreaching a maximum desired level. That is, when fluid in the storagevessel causes the float 156 (of FIG. 3) to rise, the float 156 applies arotational force to the level adjustment bar 126 (of FIG. 3). The leveladjustment bar 126 applies a downward force on the transfer linkage 128(of FIG. 3), which pulls the cartridge 130 from a position shown by FIG.6 to a position shown by FIG. 7 (of note is the deformation of thediaphragms 168). When the cartridge is positioned as shown by FIG. 7,the bottom valve face of the peanut valve 174 recedes from the firstvalve seat 180, which allows pressurized fluid to transfer from thefluid input chamber 184, to the signal chamber 200 and out the outputsignal aperture 188.

When the controller 100 is configured for operation in an indirectoperating mode, such as that shown by FIGS. 8 and 9, the controller isresponsive to fluid within the fluid storage vessel reaching a minimumdesired level. That is, when fluid in the storage vessel causes thefloat 156 to fall, the float 156 applies a rotational force to the leveladjustment bar 126. The level adjustment bar 126 applies an upward forceon the transfer linkage 128, which pushes the cartridge 130 from aposition shown by FIG. 8 to a position shown by FIG. 9 (of note is thedeformation of the diaphragms 168). When the cartridge is positioned asshown by FIG. 9, the bottom valve face of the peanut valve 174 recedesfrom the first valve seat 180, which allows pressurized fluid totransfer from the fluid input chamber 184, to the signal chamber 200 andout the output signal aperture 188.

In both cases, the controller responds by transmitting a signal,preferably in the form of pressurized fluid, to the valve controllingthe fluid level within the fluid storage vessel. When operating in thedirect mode, the pressurized fluid operates to close the valve supplyingfluid to the fluid storage vessel, when the volume of the fluid withinthe storage vessel has reached a predetermined maximum level. Whenoperating in the indirect mode, the pressurized fluid operates to openthe valve supplying fluid to the fluid storage vessel when the volume ofthe fluid within the storage vessel has reached a predetermined minimumlevel. However, those skilled in the art will appreciate that directingpressurized fluid to valve's controlling fluid levels within fluidstorage vessels is not the only method of controlling valves associatedwith fluid storage vessels.

It is contemplated that the scope of the present invention includes theresponse of the controller to the fluid level condition within the fluidstorage vessel to be the transmission of electrical signals for use incontrolling valves, such as solenoid valves. Accordingly, the selectionof a pneumatically based control environment has been made to facilitatean enhanced understanding of the present invention and does not importany limitations on the present invention.

In a preferred embodiment, the main cartridge body 165 of the invertiblepilot cartridge 130, the span control adjustment mechanism 140, and thefirst and second thrust pins 132, 136 are formed from aluminum. However,one skilled in the art will recognize, alternate materials such asbrass, ceramic, and ridged hard-wearing polymers are among those foundsuitable for the present invention.

Preferably, and independent from the choice of materials used, thedistance between the first valve seat 180 and the second valve seat 182can be changed by rotating the span control adjustment mechanism 140.Changing the distance between the first valve seat 180 and the secondvalve seat 182 changes the amount or span of movement of the float 156(of FIG. 3) needed to supply a control signal. The direction of rotationof the span control adjustment mechanism 140 determines whether thecontrol signal, provided by the controller 100, is a throttle typecontrol signal, or a snap type control signal.

By turning the span control adjustment mechanism 140 to the right of azero position, the cartridge operates in a throttle manner by providinga throttle type control signal, which allows for a more gradual changein the condition of the valve controlling the level of fluid within thestorage vessel. By turning the span control adjustment mechanism 140 tothe left of the zero position, the cartridge operates in a snap mannerby providing a snap type control signal, which operates as an “on/off”signal. The further the span control adjustment mechanism 140 ispositioned from the zero position, the larger the resulting span.

In a preferred embodiment, the controller 100 is calibrated foroperation through use of the following procedure:

-   -   1) Turn the span control adjustment mechanism 140 to a        predetermined position mark 202 (see FIG. 11), located on a top        surface of the first thrust pin 132, to set the span.    -   2) Adjust the liquid level within the storage vessel to the        desired bottom switch point.    -   3) Increase the spring force by turning the counterbalance        adjustment knob 162 (of FIG. 2) clockwise until an output signal        is provided by the controller 100.    -   4) Decrease the spring force by turning the counterbalance        adjustment knob 162 counter clockwise until the controller 100        halts the output signal.    -   5) The controller 100 is now calibrated to switch off at a        bottom switch point and back on at a predetermined distance up        from the bottom set-point. This predetermined distance is        determined by the position of the span control adjustment        mechanism 140.

In an alternate preferred embodiment, the controller 100 is calibratedfor operation through use of the following procedure:

-   -   1) Turn the span control adjustment mechanism 140 to a        predetermined position mark 202, located on a top surface of the        first thrust pin 132, to set the span.    -   2) Adjust the liquid level in the storage vessel to the desired        top switch point.    -   3) Increase the spring force by turning the counterbalance        adjustment knob 162 clockwise until an output signal is provided        by the controller 100.    -   4) The controller 100 is now calibrated to switch on at the top        switch point and off at a predetermined distance from the top        set-point. This predetermined distance is determined by the        position of the span control adjustment mechanism 140.

In an alternative preferred embodiment, the controller 100 is calibratedfor operation through use of the following procedure:

-   -   1) Turn the span control adjustment mechanism 140 to a zero        point 204 (see FIG. 11), located on a top surface of the first        thrust pin 132.    -   2) Adjust the liquid level of the storage vessel to the desired        top switch point.    -   3) Increase the spring force by turning the counterbalance        adjustment knob 162 clockwise until an output signal is provided        by the controller 100.    -   4) Lower the level of the liquid in the storage vessel to the        desired bottom level, which will cause the float 156 to be        lowered, which thereby stops the output signal.    -   5) Turn the span control adjustment mechanism 140 away from the        zero point 204 until the output signal is once again provided by        the controller 100.    -   6) Turn the adjustment knob towards the zero point until the        output signal goes to zero.

Turning to FIG. 12, shown therein is a flow chart 300, which depicts amethod of operating a liquid level controller (such as 100). The methodcommences at start process step 302 and proceeds to process step 304with a determination of an operating mode of an invertible pilotcartridge (such as 130) based on an orientation of the cartridgerelative to a cartridge housing (such as 110). At process step 306, aspan control mechanism (such as 140) is set to a neutral position (suchas 204) relative to the cartridge housing. At process step 308, a float(such as 156) communicating with the cartridge and a fluid in a storagevessel is set to a neutral position relative to the cartridge housing.At process step 310, the span control mechanism is adjusted to determinea signal response type of the cartridge, and the process concludes atend process step 312.

In a preferred embodiment, the cartridge provides a first pilotactivation feature (such as 134) of a first thrust pin (such as 132)that supports the span control mechanism, the cartridge housing includesa detachable cover (such as 116), and process step 304 includes at leasta step of: orienting the first pilot activation feature adjacent thedetachable cover to determine a direct operating mode of the cartridge;and securing the detachable cover to the cartridge housing inpreparation for operating the controller in a direct operating mode.

In an alternate preferred embodiment, the cartridge provides the firstpilot activation feature of the first thrust pin, which supports thespan control mechanism, the cartridge housing includes the detachablecover, and process step 304 includes at least a step of: orienting saidsecond pilot activation feature adjacent said detachable cover todetermine an indirect operating mode of said cartridge; and securingsaid detachable cover to said cartridge housing in preparation foroperating said liquid level controller in said indirect operating mode.

With respect to the above description, it is to be realized that theoptimum dimensional relationships for the parts of the invention, toinclude variations in size, materials, shape, form, function and mannerof operation, assembly and use, are deemed readily apparent and obviousto one skilled in the art, and all equivalent relationships to thoseillustrated in the drawings and described in the specification areintended to be encompassed by the present invention.

It will be clear that the present invention is well adapted to attainthe ends and advantages mentioned as well as those inherent therein.While presently preferred embodiments have been described for purposesof this disclosure, numerous changes may be made which will readilysuggest themselves to those skilled in the art and which are encompassedby the appended claims.

1. A method of operating a liquid level controller by steps comprising:determining an operating mode of an invertible pilot cartridge based onan orientation of said cartridge relative to a cartridge housing, inwhich said cartridge is separate and distinct from and secured withinsaid housing, and wherein said operating mode is selected from a groupconsisting of a direct operating mode and an indirect operating mode;setting a span control mechanism to a neutral position relative to saidcartridge housing, said span control mechanism secured to a proximal endof said cartridge and extending beyond the confines of said housing;adjusting a float communicating with said cartridge to a neutralposition relative to said cartridge housing; and adjusting said spancontrol mechanism to determine an amount of movement needed by saidfloat to supply a control signal, wherein said control signal is adirect control signal when said cartridge is secured for operationwithin said housing and said span control mechanism secured to saidcartridge extends beyond the confines of said housing in a firstdirection, and further wherein said control signal is an indirectcontrol signal when said cartridge is inverted and secured for operationwithin said housing such that said span control mechanism extends beyondthe confines of said housing in a second and opposite direction fromsaid first direction.
 2. The method of claim 1, in which said cartridgecomprises a first pilot activation feature supporting said span controlmechanism, said cartridge housing comprising a single detachable cover,and by further steps comprising: orienting said first pilot activationfeature adjacent said single detachable cover to determine the operatingmode of said cartridge to be in said direct operating mode; and securingsaid detachable cover to said cartridge housing in preparation foroperating said liquid level controller in said direct operating mode. 3.The method of claim 1, in which said cartridge comprises a second pilotactivation feature distal from said span control mechanism, saidcartridge housing comprising a single detachable cover, and by stepsfurther comprising: orienting said second pilot activation featureadjacent said single detachable cover to determine the operating mode ofsaid cartridge to be in said indirect operating mode; and securing saiddetachable cover to said cartridge housing in preparation for operatingsaid liquid level controller in said indirect operating mode.
 4. Themethod of claim 1, by a further step comprising, rotating said spancontrol mechanism in a counter clockwise direction relative to saidneutral position to place said cartridge into a snap signal responsetype.
 5. The method of claim 1, by a further step comprising, rotatingsaid span control mechanism in a clockwise direction relative to saidneutral position to place said cartridge into a throttle signal responsetype.
 6. The method of claim 1, in which the step of adjusting saidfloat relative to said cartridge housing comprises, rotating anadjustment nut to alter a position of said float relative to saidcartridge housing such that in response to said float being acted uponby a fluid, said cartridge provides a control signal.